The present invention relates to printing technology, and in particular to a method and means for determining a minimum pressure to print for ink delivery systems.
In a common form of inkjet printers, an ink delivery system receives ink that is then ejected in order to produce an image on print media (e.g., paper, envelope, business card, slide, and the like). The ink is supplied from a printer consumable (e.g., an ink cartridge). In order for the printer consumable to supply the ink to the ink delivery system, the printer consumable is pressurized to an appropriate level to force the supply of ink out of the printer consumable.
As the printer consumable depletes its supply of ink, the amount of pressure needed to force the supply of ink out of the printer consumable increases. Conversely, when the supply of ink is nearly full within the printer consumable, the amount of pressure needed to force the supply of ink out of the printer consumable is less. During the period of time that the ink delivery system is properly pressurizing the printer consumable (e.g. print startup latency), any pending print job is delayed until the proper pressure is achieved within the printer consumable.
Conventional approaches unduly increase the startup latency associated with many print jobs processed during the life cycle of a supply of ink included within a printer consumable. This occurs because conventional approaches assume a worst-case pressure scenario in which the printer consumable is assumed to have nearly depleted its ink supply. By doing this, many print jobs are unnecessarily delayed by a period of time before starting, while an ink delivery system over pressurizes an ink bag associated with the printer consumable. Thus, conventional approaches unduly and unnecessarily delay the startup of print jobs when the printer consumable is nearly full of its ink supply. Furthermore, by assuming a worst-case scenario for all print jobs a pump associated with the ink delivery system is overworked, which can reduce the pump""s useful life.
Therefore, there exists a need for a method and apparatus that determine a variable minimum pressure to print in an ink delivery system for a print job in order to accurately and variably delay the startup of print jobs by the real startup latency required by the ink delivery system in order to pressurize a printer consumable to an accurate level.